Drill rotating device



Dec. 17, 194-0. c. L. CHARLES 2,225,531

DRILL ROTAT ING DEVICE Filed Aug. 4, 1937 2 Sheets-Sheet l CarilC/(ar/eo f//z /MM% Dec. 17, 1940.'

c. CHARLES DRILL ROTATING DEVICE Filed Aug. 4, 1937 2 Sheets-Sheet 2Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE DRILL ROTATING DEVICEDelaware Application August 4, 1937, Serial No. 157,403

5 Claims.

This invention relates to an internal combustion percussive drill, andmore particularly to such a drill wherein means is provided for rotatingthe tool.

One feature of this invention is that it provides positive tool rotatingmeans; another feature of this invention is that the rotation isaccomplished by a motor independent of the motor doing the drilling;still another feature is that rotation of the tool is effected in steps,each step or partial rotation taking place between successive impacts ofa tool; other features and advantages of this invention will be apparentfrom the following specification and the drawings, in which:

Fig. 1 is a fragmentary vertical sectional view of an internalcombustion drill embodying this invention; Fig. 2 is a transversesectional view along the line 2-2 of Fig. 1; Fig. 3 is a side elevationof the bottom of the drill; and Fig. 4 is a fragmentary verticalsectional View of a modified form of the control means.

In order to accomplish impact drilling, as for example deep drilling inrock, it is necessary to rotate the tool in order to prevent itfromjamming in the hole. Such rotation, moreover, should be accomplishedbetween impacts on the tool, since it is practically impossible torotate a tool at the same time that it is being driven into rock or thelike. While such rotation is relatively simple in drills wherein theimpacts are accomplished pneumatically, it presents serious problems inconnection with an internal combustion drill. This is particularly truewhere the drill is of the free piston type, spring returned, since insuch case there is no source of considerable power on the upstroke ofthe piston to effect rotation of the drill by conventional rifle barmethods.

The present invention accomplishes tool rotation in steps. betweensuccessive imp-acts on the tool, by a second motor independent from thatdoing the drilling, which motor is so controlled as to efiect rotationonly between impacts.

In the particular embodiment of the invention illustrated herewith inFigs. 1 to 3, an internal combustion percussive drill is shown ascomprising a cylinder I0 having reciprocable therein a piston II. Thispiston is adapted to impart periodic impacts to a tool l2 through ananvil l3 when the drill is operated. The drill is of the type whereinmeans is provided for supplying a combustible charge to the cylinderbeneath the piston, where it is partially compressed on the down orworking strokeof the piston, and

then transferred to the combustion space there- ,abo-ve; whereappropriate ignition means may fire it at the desired time to drive thepiston downwardly. The piston is returned by the springs I4 and I5therebeneath in the cylinder, as shown. The general operation of such aninternal combustion motor for delivering periodic impacts to the tool isnot further shown or described here, since it is similar to that shownin Mould Patent 1,997,072.

A tool guide 16 is yieldingly mounted beneath the cylinder, being hereshown as adjacent thereto, by springs I! and I8 and tie rods 19 and 20extending longitudinally of the drill. Some means for absorbing theshock of the impact is necessary when the drill is raised from workingposition, since then the tool does not accomplish this. The tool guidehere accomplishes this function by being yieldingly or resilientlyconnected to the bottom of the cylinder, since when the drill is raisedand the tool l2 drops until the annular shoulder 2| thereonengages thetool holder 22, the bottom of the anvil l3 rests against the tool guideand impacts delivered to the anvil by the piston H are absorbed by thetool guide.

In order to accomplish this the tool guide, of course, moves up and downsomewhat on the tie rods.

The tool guide is here shown as having mounted therein a rotatablemember 23, which rotatable member has nonrotatably splined therein thetool I2, here shown as hexagonal. Ratchet means is provided foreffecting step by step rotation of the member 23, here being'shown ascomprising teeth 24 and a cooperating pawl 25.,

The pawl is pivotally mounted, as by the pin 25, on a longitudinallymovable member or piston 21, movement of which is accomplished by meansto be hereafter described, and is urged against the teeth 24 by thespring 28. Movement of the piston or member 21 toward the rotatablemember 23 operates, through interaction of the pawl and teeth, to effecta partial rotation of the member 23. This rotation, with respect to theView shown in Fig. 2, would be counterclockwise.

When the piston 21 moves outwardly again the pawl returns, slips overone or more teeth 24 and is in position to effect a further partialrotation upon the succeeding inward movement of the piston 21.

The piston 21 has an enlarged portion which reciprocat-es within acylinder 29, and is sealed against the walls thereof to prevent passageof fluid therearound. The piston cylinder and associated mechanism forma motor adapted to be sion of fluid under pressure thereto.

actuated by fluid under pressure admitted thereto through the port oropening 30. The piston carries therewith an extended stem 3|, on whichis slidably splined a spool valve 32. Upon admission of fluid underpressure through the opening the piston 2'! moves inwardly against thepressure of the return spring 33, the spool valve 32 not moving untilthe head 34 on the rod 3| contacts it, which is near the end of itsworking stroke. As soon as the spool valve moves inwardly it uncoversthe annular port 35, permitting exhaust of the fluid within the cylinder29 to the chamber 36, from which it is vented to atmosphere through theopening 31. As soon as no further fluid under pressure is supplied tothe inlet opening 30 the piston 21 moves outwardly under the urging ofthe spring 33, the spool valve 32 now remaining in a position whichkeeps the outlet port 35 open until it is contacted by the head of thepiston, the last part of the piston travel moving it to the positionshown in Figs. 1 and 2. Thus, periodic or step by step rotation of thetool is accomplished by this motor at intervals determined by the admis-Fluid under pressure, such as compressed air, is supplied from a sourceexternal of the hammer through a flexible conduit or hose 38 to controlmeans carried on the cylinder of the hammer, and from this control meansis transferred through the flexible hose 39 to the motor inlet opening39. The control means regulating the admission of fluid under pressureto the motor is preferably located on the cylinder I'll, so that it maybe actuated by and in accordance with reciprocation'of the piston H, andthus some sort of flexible connection is necessary between the controlmeans and the motor inlet, since the latter is movable with respect to'the former.

The control means is here shown as comprising a valve member 40interposed between the inlet 4| and outlet of the valve chamber,throughwhich the fluid passes on its way fromthe conduit '38to the conduit 39.The fluid pressure existing in the conduit 38 is exerted against the topor upper face of the valve 40, and a spring 43 is provided tosubstantiallly balance this pressure. That is, the spring should have anupward thrust only a little less than the pressure exerted downwardly bythe fluid onthe valve, so that the actuating means connected to thevalve to effect movement thereof does not have to overcome too greatresistance. The valve is here shown as having a stem which extends upthrough packing means into a chamber or cylinder 45, which chamber opensinto the cylinder beneath the piston through a port 46. The cylinder 45has therein a movable piston 41, arranged to open and shut the valve 40in accordance with its movement. The cylinder 45 beneath the pistonz'l'is open to atmosphere through the vent port Downward movement'of thepiston H on its working stroke, at the end of which the impact isdelivered to the tool l2, creates a pressure in the space in thecylinder therebeneath, which pressure is transmitted through the port 46to the cylinder or chamber 45, resulting in downward movement of thepiston 4! which causes the valve 40 to block transmission of fluid tothe motor inlet 30. The motor thereupon exhausts, as pre viouslydescribed, and the rotatable member 23 is standing still when the tooll2 receives the impact from the piston. As the piston moves up wardly,however, as a result of the rebound and the urging of the springs I 4and 15, a vacuum is created in the cylinder therebeneath, and thus inthe chamber 45. This results in upward movement of the piston 41,opening the passage through the control means to permit fluid underpressure to flow from the external source to the motor inlet 30 andeffect inward movement of the piston 21, which in turn causes a partialrotation of the tool I2 through the means heretofore described. As soonas the piston i l starts downward movement as a result of combustion ofthe charge, however, the valve 40 is again closed and the tool is againstanding still when it receives the succeeding impact. Thus partial orstep by step rotation of the tool is accomplished between impacts by themotor means, control being effected through the valve 40.

In the modified form of control means illustrated in Fig. 4 fluid issupplied under pressure through the conduit 50, whence it passes throughthe valve chamber 5! and out the conduit 52 to the motor inlet. Thevalve 53 and spring 54 are arranged similarly to the precedingmodification, but the stem of the valve 53 is here shown as connected tothe bottom plate of a Sylphon bellows 55, the interior of this bellowsbeing open to pressure within the cylinder 56 through the port 51. Thesealing means 44 may be here dispensed with, and the frictional contactbetween the piston G1 and the walls of its cylinder is also absent, sothat considerable frictional resistance to valve movement is eliminated.Full advantage may thus be taken of the changes in pressure created inthe cylinder beneath the piston, to insure positive operation of thevalve 43, and thus of the tool rotating means, at desired intervals.

While I have described certain embodiments of my invention, it is to beunderstood that itis rotating said tool; control means for said .motorcarried by said cylinder; and flexible. means connecting said motorandsaid control means.

2. An internal combustion percussive drill of thecharacter described,including: a cylinder; a piston reciprocable therein and adapted tocreate pressure beneath it on its impact stroke; a tool adapted toreceive periodic impacts from said piston during operation of saiddrill; fluid motor means for rotating said tool; means for admitting to"said motor fluid under pressure from a source'independent of saididrill; valve means controlling said admission; a chamber opening intosaid cylinder beneath said piston; a member movable in said chamber, inat least one direction in response to the pressure in said cylinder, andconnected to said valve means to efiect operation thereof; and'springmeansurging the valve means and member in the oppositedirection, wherebyrotation of said tool is effected between succeeding impacts.

3, An internal combustion percussive drill of the character described,including: a tool; a cylinder; a reciprocable member in the cylinderadapted to impart periodic impacts to said tool during operation of saiddrill; a rotatable member having said tool spllnedgjtherein; ratchetmeans adapted to eflfect step-by-step rotationloi said last mentionedmember; a; fluid motor for actuating said ratchet means; Q a source offluid under pressure adapted to begadmitted to said motor; valve meansfor controlling said admission; a movable member for operating saidvalve means, said movable member "being in a space opening into thecylinder below; the reciprocable member, and actuated by fluid, pressurecreated by movement of said reciprocable member to cause said valvemeans to move ,in one direction; and means for moving said valve meansin the other direction, whereby a step by step rotation of said tool isefiected.

4. An internal combustion percussive drill oi thecharacter described,including: a tool; a reciprocable member adapted to": impart periodicimpacts to said tool during operation of said drill; motor means forrotating said tool; control means for effecting tool-rotating movementof said motor; actuating means for the control means; spring means formoving the actuating means in one direction; and drive means connectingthe reciprocable member and the actuating means to effect movement ofthe latter in the' other direction, the connection including a passagefor fluid under pressure, whereby rotation of said tool is eflected. 5"t 5. An internal combustion percussive drill of the character described,including: a cylinder; a piston reciprocable therein; a tool adapted toreceive periodic impacts from said piston during operation of saiddrill; fluid motor means for rotating said tool; means for admitting tosaid motor fluid under pressure from a source independent of said drill;valve means controlling said admission; a spring urging the valve meansin an opening direction such as to effect operation of the fluid motor;and means open to the cylinder and actuated by pressure created on theimpact stroke of the piston for moving the valve means in closingdirection against the urging of the spring, whereby rotation of the toolis effected only between succeeding impacts.

CARL L. CHARLES.

